About 2.3 million Americans are affected by atrial fibrillation and atrial flutter (AF), a condition that causes 15% of the 700,000 strokes that occur annually in the United States. Anticoagulants like warfarin can help prevent stroke in AF patients, but these therapies can also cause bleeding in some cases. “Prediction tools, such as the CHADS2 score, have been developed to estimate stroke risk and are now recommended by clinical guideline statements,” says Mintu P. Turakhia, MD, MAS. “These guidelines, however, vary considerably in describing how stroke and bleeding risk should be evaluated and integrated into clinical decision making.” Assessing Potential Variations in Warfarin Use It has been suspected that use of warfarin in AF may vary by specialty and over time. In the American Heart Journal, Dr. Turakhia and colleagues had a study published that evaluated differences and trends in warfarin prescription by treating specialty for new AF cases. Using VA data from the TREAT-AF study, the investigators reviewed more than 141,000 participants with newly diagnosed AF in which patients had at least one internal medicine, primary care, or cardiology encounter within 90 days of their diagnosis. The primary outcome was prescription of warfarin. According to results, care of patients with new AF from cardiologists appeared to be associated with a greater likelihood of warfarin prescription when compared with care only from primary care physicians (Table 1), even after adjusting for covariates and a propensity for cardiology care. The observation was also consistent across subgroups of patients, including those who were at lowest risk for bleeding. Furthermore, warfarin prescriptions were more frequently provided to those at highest risk for stroke,...